Fix Utils.inspect and Utils.to_s to allow zero arguments

lib/liquid/utils.rb

@@ -93,41 +93,53 @@ def self.to_liquid_value(obj)
       obj
     end
 
-    def self.to_s(obj, seen = {})
-      case obj
-      when BigDecimal
-        obj.to_s("F")
-      when Hash
-        # If the custom hash implementation overrides `#to_s`, use their
-        # custom implementation. Otherwise we use Liquid's default
-        # implementation.
-        if obj.class.instance_method(:to_s) == HASH_TO_S_METHOD
-          hash_inspect(obj, seen)
+    def self.to_s(*args)
+      if args.empty?
+        super
+      else
+        obj = args[0]
+        seen = args[1] || {}
+        case obj
+        when BigDecimal
+          obj.to_s("F")
+        when Hash
+          # If the custom hash implementation overrides `#to_s`, use their
+          # custom implementation. Otherwise we use Liquid's default
+          # implementation.
+          if obj.class.instance_method(:to_s) == HASH_TO_S_METHOD
+            hash_inspect(obj, seen)
+          else
+            obj.to_s
+          end
+        when Array
+          array_inspect(obj, seen)
         else
           obj.to_s
         end
-      when Array
-        array_inspect(obj, seen)
-      else
-        obj.to_s
       end
     end
 
-    def self.inspect(obj, seen = {})
-      case obj
-      when Hash
-        # If the custom hash implementation overrides `#inspect`, use their
-        # custom implementation. Otherwise we use Liquid's default
-        # implementation.
-        if obj.class.instance_method(:inspect) == HASH_INSPECT_METHOD
-          hash_inspect(obj, seen)
+    def self.inspect(*args)
+      if args.empty?
+        super
+      else
+        obj = args[0]
+        seen = args[1] || {}
+        case obj
+        when Hash
+          # If the custom hash implementation overrides `#inspect`, use their
+          # custom implementation. Otherwise we use Liquid's default
+          # implementation.
+          if obj.class.instance_method(:inspect) == HASH_INSPECT_METHOD
+            hash_inspect(obj, seen)
+          else
+            obj.inspect
+          end
+        when Array
+          array_inspect(obj, seen)
         else
           obj.inspect
         end
-      when Array
-        array_inspect(obj, seen)
-      else
-        obj.inspect
       end
     end
 

test/unit/utils_unit_test.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class UtilsUnitTest < Minitest::Test
+  def test_inspect_without_arguments_calls_super
+    assert_equal("Liquid::Utils", Liquid::Utils.inspect)
+  end
+
+  def test_inspect_with_object
+    assert_equal('"hello"', Liquid::Utils.inspect("hello"))
+    assert_equal('123', Liquid::Utils.inspect(123))
+    assert_equal('[1, 2]', Liquid::Utils.inspect([1, 2]))
+    assert_equal('{"a"=>1}', Liquid::Utils.inspect({ "a" => 1 }))
+    assert_equal('nil', Liquid::Utils.inspect(nil))
+  end
+
+  def test_to_s_without_arguments_calls_super
+    assert_equal("Liquid::Utils", Liquid::Utils.to_s)
+  end
+
+  def test_to_s_with_object
+    assert_equal("hello", Liquid::Utils.to_s("hello"))
+    assert_equal("123", Liquid::Utils.to_s(123))
+    assert_equal("[1, 2]", Liquid::Utils.to_s([1, 2]))
+    assert_equal('{"a"=>1}', Liquid::Utils.to_s({ "a" => 1 }))
+  end
+end